Calvinists often say that man is totally depraved, but isn't it a little overdone to say that? I mean, atheists might not know God, but they'll still help little old ladies across the street. Why would they do that if they were totally depraved?

The fact that all people are totally depraved does not mean that all people will live and act at maximum levels of evil and wickedness. There is a misun­derstanding of the terms here that is easily resolved by turning to its most prominent source, the Canons of Dort. As the foremost summary of the so-called Five Points of Calvinism, the Canons fea­ture five chapters dealing with the ele­ments of the well-known acronym TULIP. The "T" stands for "Total De­pravity" and we find this discussed in chap. III/IV. In Article 3 we confess,

Therefore all men are conceived in sin and are born as children of wrath, incapable of any saving good, inclined to evil, dead in sins, and slaves of sin.

This description is later referred to in the same article as the "depraved nature" of man.

Notice, however, that the depraved nature of man does not necessarily mean a display of maximum evil. Man's nature is incapable of any "saving good" but may still do some "nice" things. Man's nature is "inclined" to evil, but doesn't neces­sarily act on this inclination all the time. Inclination is different than acting and doing. What is implicit here becomes explicit in Article 4 where we confess,

To be sure, there is left in man after the fall, some light of nature, whereby he retains some notions about God, about natural things, and about the difference between what is honourable and shameful, and shows some regard for virtue and outward order.

This "light of nature" then, is what helps explain the atheist helping the little old lady cross the street. Though it is never used prop­erly by fallen man and ultimately ren­ders him inexcusable before God, yet this remaining light of nature serves to ex­plain in part the regard for virtue and order even in the life of many unbeliev­ers. The other and more significant rea­son for any decency of behaviour on the part of unbelievers is the hand of God in holding them back from giving in to those sinful inclinations all the time (Matthew 10:28-31; Romans 8:38-39).

Total depravity should not be un­derstood as the maximum evil a person can commit, but rather that the evil of sin has effected every part of man's nature. There is not one part of man's heart, soul, mind, or body that has not been per­verted by sin, and thus it is the total man that is depraved. This total depravity af­fects the whole person and leaves him in­capable of doing anything that pleases God, hence we are all dead in sin (Ephesians 2:1-3). Total depravity of mankind does not equal maximum depravity in all peo­ple but rather refers to the complete, negative effect that sin has had on all of man's nature. Where once man's nature was inclined in every facet to do God's will, it is now inclined in every facet to sin and disobedience.